I Am An Animal Embryologist

A question that I get almost every time I explain to people what I do as part of the Reproductive Sciences team at the Institute for Conservation Research is, “How do you do that?” Well, it’s actually quite a simple answer.

Most people know someone who has had in vitro fertilization (IVF) or has gone through the emotional procedure themselves at a fertility clinic to get pregnant. As an animal embryologist, I perform the same procedure, but for endangered species rather than humans. Although my 4-year-old daughter thinks I pet animals at work all day, the fact is, I don’t.

What does an embryologist do all day?

I work on an inverted microscope with micromanipulators the majority of my time. The inverted microscope has its light source and condenser above the stage pointing down, while the objectives are below the stage pointing up, which is the opposite of the more common light microscope. This configuration allows me to see living cells, in my case sperm and eggs, under natural conditions in a petri dish.

I obviously cannot manipulate these sperm or eggs with my own hands so I use a micromanipulator. This robotic device allows me to physically interact with a sample under a microscope when a level of precision of movement is necessary that cannot be achieved by hand. In my case, I need micromanipulators to perform intracytoplasmic sperm injection (ICSI, pronounced icksee) to fertilize eggs of exotic species.

The manipulation system consists of two joysticks, one on each side of the microscope, with which I control the movements of two tiny glass pipettes called microtools. The tips of the microtools are extremely small - about the diameter of a human hair. One of them creates a vacuum that holds a single egg firmly but without damaging its delicate outer membrane called the zona pellucida. The other microtool is manipulated with its joystick to pick up a single sperm and inject it into the egg.

The egg, sperm and microtool tips are magnified 800 times so I can see and control this exacting maneuver. You can imagine that at this magnification, any vibration from other equipment in the lab, someone walking through the lab, or the air conditioner could make this procedure impossible. Did I mention that all of this is done on a floating table, otherwise known as an anti-vibration table? This extremely heavy table sits on four pneumatic legs or air pistons that eliminate movements on the working surface. My bench just floats!

Sometimes it feels like I am playing a video arcade game, using the floor pedals and complex joystick controllers on either side of the microscope. I even have a laser on my microscope that makes loud popping noises when I press the floor pedal.

So, what’s the laser used for? The laser operates at a harmless wavelength to dissect a hole in the zona pellucida to help sperm fertilize an egg on its own during conventional in vitro fertilization rather than ICSI. I also use the laser to help an embryo hatch out of its zona pellucida to facilitate implantation in the uterus.

I know that this may sound tedious or complicated to some, but I very much enjoy it. How many people can say that they have attempted ICSI on animals like a rhino, ring-tailed lemur, clouded leopard or Somali wild ass? The answer is, not very many, and that is rewarding in itself.

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